Protective effects of carnosine on dehydroascorbate-induced structural alteration and opacity of lens crystallins: important implications of carnosine pleiotropic functions to combat cataractogenesis

The high level of dehydroascorbic acid (DHA) in the lenticular tissue is an important risk factor for the development of age-related cataracts. In this study, the effects of DHA on structure and function of lens crystallins were studied in the presence of carnosine using gel mobility shift assay, different spectroscopic techniques, and lens culture analysis. The DHA-induced unfolding and aggregation of lens proteins were largely prevented by this endogenous dipeptide. The ability of carnosine to preserve native protein structure upon exposure to DHA suggests the essential role of this dipeptide in prevention of the senile cataract development. Although the DHA-modified α-crystallin was characterized by altered chaperone activity, functionality of this protein was significantly restored in the presence of carnosine. The increased proteolytic instability of DHA-modified lens proteins was also attenuated in the presence of carnosine. Furthermore, the assessment of lens culture suggested that DHA can induce significant lens opacity which can be prevented by carnosine. These observations can be explained by the pleiotropic functions of this endogenous and pharmaceutical compound, notably by its anti-glycation and anti-aggregation properties. In summary, our study suggests that carnosine may have therapeutic potential in preventing senile cataracts linked with the increased lenticular DHA generation, particularly under pathological conditions associated with the oxidative stress.     

Sleep habits of Iranian pre-school children in an urban area: Late sleeping and sleep debt in children

Using BEARS (Bedtime problems, Excessive sleepiness, Awakenings during the night, Regularity of sleep, Snoring), and CSHQ (Children’s Sleep Habits Questionnaires) screening tools with 224 participants revealed that Iranian children have shorter night sleep duration than expected (9.54 vs 12 h) for their age group. Earlier sleepers had longer night sleep duration (10:36 ± 1:12; 9:12 ± 1:06 h, P > 0.001), and total daily sleep time (11:36 ± 1:42; 10:36 ± 1:30 h, P = 0.005) than late sleepers. A majority (85%) of naptakers had sleep bedtime of 22:00 or later. The poor sleep quality of Iranian preschool children is probably due to cultural characteristics, climate differences, or harmful sleep habits.

     

Interspecific relationships of the genus<Emphasis Type="Italic"> Cicer</Emphasis> L. (Fabaceae) based on<Emphasis Type="Italic"> trn</Emphasis>T-F sequences

The trnT-F region in chloroplasts was sequenced to elucidate interspecific phylogenetic relationships in the genus Cicer. Twenty-five species representing four sections and two outgroups were analyzed. A phylogenetic analysis revealed three major clades in the genus Cicer. Inferred phylogenetic relationships support multiple origins of annual species in the genus Cicer. Low variation within the most perennial species in the sequence regions suggests they may have originated during a period of rapid diversification after the genus arose. High levels of sequence divergence, biogeographical patterns and morphological traits between African and Eurasian groups of species suggest that Cicer may have independently diverged on each continent. Phylogenetic analysis of sequence data did not support the monophyly of the currently recognized sections and indicated the need for a revision of the infrageneric classification.Communicated by C. Möllers     

Application of zeolite and geohumus superabsorbent on establishment and some growth indices of Nitraria schoberi L.

Using Superabsorbent is one of the solutions to water shortages in arid and semi-arid regions. In order to evaluate the effect of zeolite and geohumus on the growth of Nitraria schoberi L. species, a factorial experiment in a completely randomized design was conducted with nine replications in Kashan city. The treatments consisted of various zeolite levels (0, 10 and 15 wt%) and geohumus (0, 100, 150, 250 gr for hole) and irrigation (normal irrigation, low irrigation). This study showed that superabsorbent application has a positive effect on establishment and other indices such as plant height, large and small canopy diameter and collar diameter. The highest survival percentage was observed in superabsorbent application (100%) and the lowest was measured in control treatment of low irrigation (the soil free of modifying substances) (78%). Also, the most growth indices of the plant are related to the treatment of 250 g geohumus with low irrigation treatment. Based on the results, it was found that adding superabsorbent on soil causes more establishment and improves vegetative growth traits. Also, considering the economical price of zeolite superabsorbent compared to geohumus as well as its abundance in Iran, it is recommended to use in order to increase irrigation intervals and reduce costs in desertification projects.     

Analysis of DNA fragmentation in mouse embryos exposed to an extremely low-frequency electromagnetic field

Effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on DNA damage in biological systems are still a matter of dispute. The aim of the present study was to investigate the possible effect of electromagnetic field exposure on DNA fragmentation in cells (blastomers) of mouse blastocysts. Eighty female NMRI mice were randomly divided into 2 groups of 40 animals each. The control group was left unexposed whereas the animals in the EMF-group were exposed to a 50-Hz EMF at 0.5?mT 4?h per day, 6 days a week for a duration of 2 weeks. After the 8(th) day of exposure, the female mice in both groups were superovulated (with injections of pregnant mare serum gonadotropin and human chorionic gonadotropin) and then mated overnight. At approximately 4 days after mating (102?h after the human chorionic gonadotropin treatment), blastocysts were obtained by flushing the uterus horns. The mean numbers of pregnant mice, blastocysts after flushing, blastomers within the blastocysts, and the DNA fragmentation index following staining in both groups were compared using statistical methods (SPSS, the Chi-square test, the Student's t-test and the Mann-Whitney U-test, P?相似文献   

CBL Linker Region and RING Finger Mutations Lead to Enhanced Granulocyte-Macrophage Colony-stimulating Factor (GM-CSF) Signaling via Elevated Levels of JAK2 and LYN

Juvenile myelomonocytic leukemia (JMML) is characterized by hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF). SHP2, NF-1, KRAS, and NRAS are mutated in JMML patients, leading to aberrant regulation of RAS signaling. A subset of JMML patients harbor CBL mutations associated with 11q acquired uniparental disomy. Many of these mutations are in the linker region and the RING finger of CBL, leading to a loss of E3 ligase activity. We investigated the mechanism by which CBL-Y371H, a linker region mutant, and CBL-C384R, a RING finger mutant, lead to enhanced GM-CSF signaling. Expression of CBL mutants in the TF-1 cell line resulted in enhanced survival in the absence of GM-CSF. Cells expressing CBL mutations displayed increased phosphorylation of GM-CSF receptor βc subunit in response to stimulation, although expression of total GM-CSFR βc was lower. This suggested enhanced kinase activity downstream of GM-CSFR. JAK2 and LYN kinase expression is elevated in CBL-Y371H and CBL-C384R mutant cells, resulting in enhanced phosphorylation of CBL and S6 in response to GM-CSF stimulation. Incubation with the JAK2 inhibitor, TG101348, abolished the increased phosphorylation of GM-CSFR βc in cells expressing CBL mutants, whereas treatment with the SRC kinase inhibitor dasatinib resulted in equalization of GM-CSFR βc phosphorylation signal between wild type CBL and CBL mutant samples. Dasatinib treatment inhibited the elevated phosphorylation of CBL-Y371H and CBL-C384R mutants. Our study indicates that CBL linker and RING finger mutants lead to enhanced GM-CSF signaling due to elevated kinase expression, which can be blocked using small molecule inhibitors targeting specific downstream pathways.     

Prevalence of congenital hypothyroidism in Isfahan, Iran: results of a survey on 20,000 neonates

AIMS: To evaluate the prevalence of congenital hypothyroidism (CH) in a screening program performed for the first time in Isfahan, Iran. METHODS: From May 2002 to December 2002, T4 and TSH serum concentrations of 20,000 3- to 7-day-old newborns, born in all 17 hospitals of the city, were measured by radioimmunoassay and immunoradiometric assay, respectively. The newborns with abnormal screening results (TSH >20 mIU/l, T4 <6.5 microg/dl and based on the weight) were re-examined. RESULTS: Of 531 recalled subjects (recall rate 2.6%), 54 were confirmed to be hypothyroid, showing a prevalence of 1:370 for CH. CONCLUSION: Considering the high frequency of CH, the necessity of implementing a routine screening program in the healthcare system of Isfahan Province is emphasized.     

Resistance of grapevine to the erineum strain of Colomerus vitis (Acari: Eriophyidae) in western Iran and its correlation with plant features

The interaction of grape erineum mite (GEM), Colomerus vitis Pagenstecher (Acari: Eriophyidae), with grape was investigated in the laboratory. We studied some plant morphological biochemical features potentially related to vine resistance/tolerance of eight native grapevine cultivars, extensively cultivated in western Iran, and two non-native cultivars. Free-choice experiments indicated that the cultivars Shahani, Flame seedless and Yaghuti were colonized by lower levels of GEM, whereas Muscat Gordo, Gazne and White Thompson seedless hosted denser populations. These differences between cultivars may be due to differential attractiveness to GEM, possibly associated with plant biochemical and morphological traits. In no-choice assays with six grapevine cultivars, mite population development and some cultivar features were assessed. Mite populations grew fastest on Gazne and Muscat Gordo, and slowest on Yaghuti and Shahani. The degree of mite infestation was associated with reduction of leaf area, increase of leaf weight, shortening of shoots and more numerous erinea: these features were larger on the most infested Gazne, whereas morphological features of Shahani and Yaghuti were scarcely affected by GEM infestation. Also trichome type and density of the assayed cultivars appeared to be related to mite density: the most infested cultivars (Gazne and Muscat Gordo) displayed higher ranks of blade and vein hairs and lower ranks of blade and vein bristles and domatia. No correlation was found between mite density and leaf thickness of mature leaves. The amount of leaf waxes was highest in Shahani and Yaghuti, which displayed the lowest mite density, the fewest erinea and the largest leaves. Carbohydrate amount of uninfested leaves was lowest on the least infested Shahani and highest on the most infested Gazne; phenols increased in leaves of Shahani and decreased in those of Gazne after mite infestation. Finally, cultivars also appeared to influence some morphological traits of the mites: larger specimens were detected on White Thompson seedless, Flame seedless and Gazne, whereas smaller mites were found on leaves of the less infested Yaghuti and Shahani. These results indicate that leaf hairiness, leaf wax and carbohydrate contents may be useful tools for a preliminary screening among vine cultivars and help predict resistance/tolerance to GEM. Shahani and Yaghuti seem quite promising for developing grape resistance programs against GEM in western Iran.